package store

import (
	"context"
	"errors"
	"time"

	"github.com/jackc/pgx/v5"
)

// Media stores metadata of an uploaded file. The file bytes live in the
// media storage backend (see internal/media), referenced by StorageKey.
type Media struct {
	ID          int64
	UploaderID  int64
	Filename    string
	ContentType string
	Size        int64
	StorageKey  string
	ThumbKey    string
	CreatedAt   time.Time
}

// CreateMedia inserts a media record and returns it with its ID.
func (s *Store) CreateMedia(ctx context.Context, m Media) (*Media, error) {
	err := s.pool.QueryRow(ctx, `
       INSERT INTO media(uploader_id, filename, content_type, size, storage_key, thumb_key)
       VALUES($1, $2, $3, $4, $5, $6)
       RETURNING id, created_at
   `, m.UploaderID, m.Filename, m.ContentType, m.Size, m.StorageKey, nullableString(m.ThumbKey)).Scan(&m.ID, &m.CreatedAt)
	if err != nil {
		return nil, err
	}
	return &m, nil
}

// GetMediaByID retrieves a media record or returns ErrNotFound.
func (s *Store) GetMediaByID(ctx context.Context, id int64) (*Media, error) {
	var m Media
	var thumbKey *string
	err := s.pool.QueryRow(ctx, `
       SELECT id, uploader_id, filename, content_type, size, storage_key, thumb_key, created_at
       FROM media WHERE id=$1
   `, id).Scan(&m.ID, &m.UploaderID, &m.Filename, &m.ContentType, &m.Size, &m.StorageKey, &thumbKey, &m.CreatedAt)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, ErrNotFound
		}
		return nil, err
	}
	if thumbKey != nil {
		m.ThumbKey = *thumbKey
	}
	return &m, nil
}

func nullableString(s string) *string {
	if s == "" {
		return nil
	}
	return &s
}